Recently, wireless data, entertainment and mobile communications technologies have become increasingly prevalent, particularly in the household environment. The convergence of these wireless data, entertainment and mobile communications within the home has created the need for merging many disparate devices into a single wireless network architecture capable of seamlessly supporting and integrating the requirements of all of these devices. Seamless connectivity and rapid transfer of data, without confusing cables and wires for various interfaces that will not and cannot talk to each other, is a compelling proposition for a broad market.
Ideally, each of these device will cost effectively be capable of automatically discovering and securely communicating with every other device within its environment, and be capable of meeting any future connectivity requirements.
To that end, communication industry consortia such as the MultiBand OFDM Alliance (MBOA), Digital Living Network Alliance (DLNA) and the WiMedia Alliance are establishing design guidelines and standards to ensure interoperability of these wireless devices. For example, Wireless 1394, Wireless USB, and native IP-based applications are currently under development based on Ultrawideband (UWB) radio or WiMedia Convergence Platform.
Although it began as a military application dating from the 1960s, UWB has recently been utilized as a high data rate (480+ Mbps), short-range (up to 20 meters) technology that is well suited to emerging applications in the consumer electronics, personal computing and mobile markets. When compared to other existing and nascent technologies capable wireless connectivity, the performance benefits of UWB are compelling. For example, transferring a 1 Gbyte file full of vacation pictures from a digital camera to a photo take merely seconds with UWB compared to hours using other currently available, technologies (i.e. Bluetooth) and consume far less battery power in doing so.
Typically, devices which employ UWB utilize a fixed channel bandwidth that is static in frequency, or a fixed channel bandwidth that can be frequency agile. In either case, the bandwidth utilized by a device must remain substantially fixed. Thus, the range and data rate of the device is, for the most part, determined by the modulation/coding of the signal, and the power with which the signal is transmitted. Additionally, because the bandwidth utilized by these devices is fixed, an architecture for these devices does not readily scale down to lower transmit power, lower bandwidth and performance or scale up to higher transmit power, wider bandwidth and performance. This architecture forces devices that do not need to transmit over a long range or cannot tolerate high power consumption to use suboptimal solutions, while compromising the performance of higher-end devices that need to operate at higher performance points.
Furthermore, this architecture exacerbates interoperability problems between wireless devices. Interference in a given spectrum varies with power levels, bandwidth ratios, and medium access methods and without any means of policing how systems behave. Applications that require significant wireless bandwidth are subject to the threat of punishing interference from a variety of devices, and devices in one network may be subject to interference from devices in another network, depending on the strength and location of these devices. Additionally, in many cases devices which employ a fixed frequency cannot interoperate with devices or networks which utilize different bandwidths.
Thus, as can be seen, there is a need for an architecture for radio devices and systems which allow wireless devices to be scaled while enabling interoperability between the devices and systems. A scalable architecture allows a system designer to mix small and wide bandwidth devices in a way that makes them interoperable, and allows a designer to take advantage of the unique attributes of each.